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Re: [v3] more istream::ignore cleanups
Benjamin Kosnik wrote:
Are those discussions recorded somewhere? In the LWG reflector? I would be
interested in the details: actually, strictly speaking, the whole LFS
idea is not compatible with the C++ standard in the present form...
... on the archives of this list.
See:
http://gcc.gnu.org/ml/libstdc++/2004-09/msg00110.html
http://gcc.gnu.org/ml/libstdc++/2004-09/msg00126.html
etc, etc, etc.
Try google with (streamsize lfs site:gcc.gnu.org)
Ok, you convinced me that probably this is the most consistent solution.
The below is what I'm finishing regtesting.
Paolo.
//////////////////
2005-01-11 Paolo Carlini <pcarlini@suse.de>
Benjamin Kosnik <bkoz@redhat.com>
* src/istream.cc (basic_istream<char>::ignore(streamsize),
basic_istream<char>::ignore(streamsize, int_type),
basic_istream<wchar_t>::ignore(streamsize),
basic_istream<wchar_t>::ignore(streamsize, int_type)): In case
more than numeric_limits<streamsize>::max() chars are skipped,
set _M_gcount = max().
* include/bits/istream.tcc (ignore(streamsize), ignore(streamsize,
int_type)): Likewise; keep simple, don't forward.
diff -urN libstdc++-v3-orig/include/bits/istream.tcc libstdc++-v3/include/bits/istream.tcc
--- libstdc++-v3-orig/include/bits/istream.tcc 2005-01-11 17:21:24.000000000 +0100
+++ libstdc++-v3/include/bits/istream.tcc 2005-01-11 20:33:39.000000000 +0100
@@ -671,9 +671,6 @@
basic_istream<_CharT, _Traits>::
ignore(streamsize __n)
{
- if (__n == 1)
- return ignore();
-
_M_gcount = 0;
sentry __cerb(*this, true);
if (__cerb && __n > 0)
@@ -692,6 +689,7 @@
// by definition, when more than 2G chars are actually ignored,
// _M_gcount (the return value of gcount, that is) cannot be
// really correct, being unavoidably too small.
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -702,11 +700,17 @@
}
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
}
@@ -723,9 +727,6 @@
basic_istream<_CharT, _Traits>::
ignore(streamsize __n, int_type __delim)
{
- if (traits_type::eq_int_type(__delim, traits_type::eof()))
- return ignore(__n);
-
_M_gcount = 0;
sentry __cerb(*this, true);
if (__cerb && __n > 0)
@@ -738,6 +739,7 @@
int_type __c = __sb->sgetc();
// See comment above.
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -750,16 +752,23 @@
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof)
&& !traits_type::eq_int_type(__c, __delim))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
else if (traits_type::eq_int_type(__c, __delim))
{
- ++_M_gcount;
+ if (_M_gcount < numeric_limits<streamsize>::max())
+ ++_M_gcount;
__sb->sbumpc();
}
}
diff -urN libstdc++-v3-orig/src/istream.cc libstdc++-v3/src/istream.cc
--- libstdc++-v3-orig/src/istream.cc 2005-01-11 17:23:00.000000000 +0100
+++ libstdc++-v3/src/istream.cc 2005-01-11 20:06:20.000000000 +0100
@@ -125,6 +125,7 @@
int_type __c = __sb->sgetc();
// See comment in istream.tcc.
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -147,11 +148,17 @@
}
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
}
@@ -183,6 +190,7 @@
__streambuf_type* __sb = this->rdbuf();
int_type __c = __sb->sgetc();
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -212,16 +220,23 @@
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof)
&& !traits_type::eq_int_type(__c, __delim))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
else if (traits_type::eq_int_type(__c, __delim))
{
- ++_M_gcount;
+ if (_M_gcount < numeric_limits<streamsize>::max())
+ ++_M_gcount;
__sb->sbumpc();
}
}
@@ -403,6 +418,7 @@
__streambuf_type* __sb = this->rdbuf();
int_type __c = __sb->sgetc();
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -425,11 +441,17 @@
}
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
}
@@ -461,6 +483,7 @@
__streambuf_type* __sb = this->rdbuf();
int_type __c = __sb->sgetc();
+ bool __large_ignore = false;
while (true)
{
while (_M_gcount < __n
@@ -490,16 +513,23 @@
if (__n == numeric_limits<streamsize>::max()
&& !traits_type::eq_int_type(__c, __eof)
&& !traits_type::eq_int_type(__c, __delim))
- _M_gcount = numeric_limits<streamsize>::min();
+ {
+ _M_gcount = numeric_limits<streamsize>::min();
+ __large_ignore = true;
+ }
else
break;
}
+ if (__large_ignore)
+ _M_gcount = numeric_limits<streamsize>::max();
+
if (traits_type::eq_int_type(__c, __eof))
__err |= ios_base::eofbit;
else if (traits_type::eq_int_type(__c, __delim))
{
- ++_M_gcount;
+ if (_M_gcount < numeric_limits<streamsize>::max())
+ ++_M_gcount;
__sb->sbumpc();
}
}